Lesson 1: How to Solve Basic Algebraic Equations

Solve the following equation. A − 7 = 17

24

Solve for R in the following equation. R/5 = 6

30

Find the value of the variable A in the equation A=BH/2 if B = 13 and H = 5.

32.5

Solve the following equation. A + 17 = 20

A = 3

A × B = AB. If AB = 63 and B = 12.6, what is the value of A? a.

A = 5

Select the correct Ohm's Law formula that will solve for E when only I and R are known.

E = Ix R

Given E = I × R and P = E × I, select the formula that will solve for E when only I and P are known.

E = P/I

Given E = I × R and P = E × I, select the formula that will solve for E when only R and P are known.

E = √PxR

Solve the following simple equations for X. 3X = A − B

X = (A-B)/3

Solve the following simple equations for X. YX = A − B

X = (A-B)/Y

Solve the following for X. 45X = 120/2

X = 1.33

Solve the following for X. X + (A + B − 2) = 100

X = 102 − A − B

Solve the following for X. X - (7/2) = 120

X = 123.5

Solve the following for X. 128/X = 64

X = 2.0

Solve the following equation. 15Y = 90

Y = 6

A(n) ? is a shorthand method for writing a mathematical rule.

formula

? is expressed as the sum of a given number of quantities.

Addition

Solve the following for X. (A + B) X = 27

X = 27/(A+B)

To solve the equation below, a person must ? each side of the equation. A − 7 = 17

add 7 to

The multiplication of two or more quantities may be expressed as the ? of the same quantities.

product

Division of two quantities is expressed as the ? of those two quantities.

quotient

To solve the equation below, a person must ? each side of the equation. A + 17 = 20

subtract 17 from

Given: EL = IN x RN/RN+RL IN = 10 Amps RN = 2 Ω RL = 3 Ω Solve for EL

EL = 4.0 V

Subtraction is expressed as the ? two quantities.

difference between

Solve the following simple equations for X. (3X)/3 = (4-1)/3

1

Solve the following simple equations for X. 3X/3 = (A-1)/3

X = (A-1)/3

Given: E = IR I = 150 µA R = 450 kΩ Solve for: E (in volts)

67.5 Volts

Given E = I × R, select the formula that will solve for R when only E and I are known.

R = E/I

If a person multiplies one side of an equation by five, what must he or she do to the other side of the equation?

Multiply by five.

Change the following rule into a formula.The power in watts (P) in a circuit is equal to the voltage (E) multiplied by the current (I).

P = E × I

Change the following rule into a formula.The resistance in ohms (R) in a circuit is equal to the voltage (E) divided by the current (I).

R = E/I

Given E = I × R and P = E × I, select the formula that will solve for R when only E and P are known.

R = E2/P

Given E = I × R and P = E × I, select the formula that will solve for R when only I and P are known.

R = P/I2

How could someone prove he or she answered the previous question correctly?

Substitute the calculated values into the original equation and verify equality.